1. Field of the Invention
The present invention relates to a signal relay apparatus, a method, and a computer readable medium; specifically to a signal relay apparatus, a method, and a computer readable medium capable of dynamically adjusting a gain for a wireless network.
2. Descriptions of the Related Art
Currently, a radio access network mainly consists of multiple base stations (BS) and subscriber stations (SS). With a network in which the base stations are distributed at suitable locations, the transmission should be performed in the whole area under limited transmission power. However, a shadow fading effect of signals caused by topography or man-made buildings has to be considered while a coverage range of the base stations is planned. For example, If signals are blocked by huge buildings, an effective coverage range must be reduced appropriately to ensure that the subscriber stations can still maintain transmission in its range. Alternatively, a signal relay apparatus is set up to relay signals.
FIG. 1 shows a diagram of a conventional signal relay apparatus 1 comprising a receiver 11, an amplifier 12 and a transmitter 13. The receiver 11 is configured to receive a wireless signal 14 and to convert the wireless signal 14 into a digital signal 15. The amplifier 12 is configured to amplify the digital signal 15 to generate an amplified signal 16. Finally, the transmitter 13 transmits the amplified signal 16 to overcome the shadow fading effect of signals and broaden a signal transmission range.
However, although the conventional signal relay apparatus 1 can effectively overcome the shadow fading effect of signals and broaden a signal transmission range, it can not dynamically adjust a gain of the amplifier 12 so that power consumption is considerable. On the other hand, since the amplifier 12 amplifies all received signals without difference, noise is also amplified. It makes de-modulation difficult for a device receiving the amplified signal 16. Consequently, how to dynamically adjust the gain of the amplifier 12 according to received signals and to further enhance an overall performance of the signal relay apparatus is still an object for the industry to endeavor.